The present invention relates to the fastening of a turbine housing to foundation crossbeams and to the bearing housing
In the design of turbines which is conventional today, the axial forces are conveyed into the foundation crossbeam via transverse wedges, the bearing housing and the foundation plate or via foundation bolts and retaining blocks. In a known type of fastening of this kind, the fixed point, that is the point at which the axial stresses engage on the bearing housing, is located at the height of the shaft line. An unduly high torsional stress on the crossbeam can arise as a result. Also, because of the tilting movements associated therewith, the blade clearances and the play at the shaft seals can be changed so that blade-scraping and consequently uneven running of the shaft line occur. Moreover, there is also an increase in the axial forces which act on the fastening, especially in high-powered steam turbines, as a result of the action forces of the steam lines connected to the turbine housing and because of the increased friction arising during expansions of the housings as a result of their ever greater weights. However, since the space conditions, for example between the medium-pressure and low-pressure parts of the turbine, are restricted for constructional reasons, there is a limit to a corresponding larger dimensioning of the crossbeam of the foundation.
The object of the present invention is therefore to shift the fixed point for the stationary parts of a turbine, so that a high torsional stress on the foundation crossbeam and consequently undue movement of the bearing housing at the mounting point are avoided.
The abovementioned object and others are achieved, according to the invention, due to the fact that there is on the turbine housing at least one supporting rib which is connected rigidly in an axial direction to the foundation crossbeam via a sway brace and a retaining device. Further a mounting lug of the turbine housing is mounted axially movably on a supporting face of the bearing housing.
Because the turbine housing is fastened according to the present invention to the crossbeam via supporting ribs and sway braces, changes to the foundation crossbeam which are difficult and expensive in terms of construction can be avoided. In addition, the turbine housing is prevented from lifting on one side as a result of the occurence of tilting movements of the foundation crossbeam together with the bearing housing fastened thereto.
According to a further embodiment the sway braces are adjustable axially via eccentric bushes.
Precision adjustment, without play, is possible by means of this design.
It is also advantageous if set screws are located at the place of support on the foundation crossbeam.
The fixed point can thereby be adjusted in a simple way during assembly.